content: /*
   * Copyright 2011-2016 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package ix;
  
  import java.util.Iterator;
  
  /**
   * Suppress or throw when the remove() is called.
   *
   * @param <T> the value type
   */
  final class IxReadOnly<T> extends IxSource<T, T> {
  
      final boolean silent;
  
      IxReadOnly(Iterable<T> source, boolean silent) {
          super(source);
          this.silent = silent;
      }
  
      @Override
      public Iterator<T> iterator() {
          if (silent) {
              return new ReadOnlySilentIterator<T>(source.iterator());
          }
          return new ReadOnlyThrowingIterator<T>(source.iterator());
      }
  
      static final class ReadOnlySilentIterator<T> implements Iterator<T> {
  
          final Iterator<T> source;
  
          ReadOnlySilentIterator(Iterator<T> source) {
              this.source = source;
          }
  
          @Override
          public boolean hasNext() {
              return source.hasNext();
          }
  
          @Override
          public T next() {
              return source.next();
          }
  
          @Override
          public void remove() {
              // deliberately ignored
          }
      }
  
      static final class ReadOnlyThrowingIterator<T> implements Iterator<T> {
  
          final Iterator<T> source;
  
          ReadOnlyThrowingIterator(Iterator<T> source) {
              this.source = source;
          }
  
          @Override
          public boolean hasNext() {
              return source.hasNext();
          }
  
          @Override
          public T next() {
              return source.next();
          }
  
          @Override
          public void remove() {
              throw new UnsupportedOperationException();
          }
      }
  }
  